What is Calf Emphasis effect?

[unfa]

I've installed Ubuntu Studio 14.04 Beta 2 and started playing around with the exciting new stuff.
Then I found this - it looks like some specialized hard-coded EQ:

Calf Emphasis audio plugin GUI

CalfEmphasis.jpg (228.02 KiB) Viewed 819 times

I've heard that vinyl masters needed a special "tilt EQ" applied to reduce bass and emphesize the tops, and that a reversed process was applied during playback.
This looks like the case, but I don't quite get what are the availabile presets...

Calf Emphasis filter options

options.jpg (8.55 KiB) Viewed 819 times

and why there's a "Compact Disc (CD)" option - that seems much different form the rest, because it has only a high shelf-like filter applied with bass left untouched.

Every filter has a "Production" and "Reproduction" mode - they seem to apply opposite processing (basically reversing each other's effects).

I tried to find some documentation for this unit, but it seems to be fresh enough to not have one - so I decided to ask here.

Do you know what this exacly does and what are possible applications of this processor?

The one I can think of is preparing an album master to be pressed on vinyl

Another is applying selective distortion - first you apply a filter in "Production" then you distor the signal and then apply the "Reproduction".

Bless ya!

[bluebell]

Looks like curves for different cutting machines for the production of vinyl records.

See https://en.wikipedia.org/wiki/RIAA_equalization

[bazsound]

Its meant for records.

If your producing Music that is to be processed for vyna, you would use the curves in that calf plugin. due to the nature of vynal bass frequencies must be reduced and treble boosted.

The reverse of these filters then get used when playing back the record.

[Thad E Ginathom]

It's an interesting discovery!

Yes, records have to have this EQ applied, and without it, they would not physically play. The bass would have the stylus jumping out of the groove. So much for the new generation who think that vinyl is all pure analogue sound, untouched by human hand!

This, apart from amplifying the tiny signal from a turntable cartridge, is what a phono pre-amp does: it applies this RIAA EQ curve to correct the curve made before manufacture. If you have an older hifi amp it might have a "phono" input, which incorporates such a pre-amp. Pre-CD days, they all did, as LPs were our primary, or even only, source.

The settings other than RIAA date back to before it became the universal standard. I don't know when that was. I think it had happened when we were still spinning fragile shellac discs at 78RPM, and even playing them with needles, rather than tiny chunks of diamond!

The last time I did any digitising of vinyl, I found that Audacity has an RIAA filter which compared favourably with my phono pre-amp. This is another tool to try

[aprzekaz]

Interesting stuff here. I have a Behringer uca222 that has 2 RCA inputs and 2 RCA outputs. So I guess If I plug a turntable into it so I can sample an actual vinyl record, I'll want to apply this effect since the uca222 probably doesn't have this eq built in. But I guess I also assume that if that turntable is plugged into a DJ mixer first then into my soundcard, the DJ mixer probably does apply this curve automatically. Is this true? It's cool that there are other curves in case I ever come across any really old records but RIAA should be the standard for most lp's from the 60's and up it seems. I guess if anyone wants to master their stuff for vinyl production this is useful for that as well. Definitely cool to know this. So does it make sense to apply the CD curve for sampling from a CD? It seems if i'm just ripping from the CD to WAV files no kind of eq should be necessary. I'm I correct in all this

[bazsound]

Interesting stuff here. I have a Behringer uca222 that has 2 RCA inputs and 2 RCA outputs. So I guess If I plug a turntable into it so I can sample an actual vinyl record, I'll want to apply this effect since the uca222 probably doesn't have this eq built in. But I guess I also assume that if that turntable is plugged into a DJ mixer first then into my soundcard, the DJ mixer probably does apply this curve automatically. Is this true? It's cool that there are other curves in case I ever come across any really old records but RIAA should be the standard for most lp's from the 60's and up it seems. I guess if anyone wants to master their stuff for vinyl production this is useful for that as well. Definitely cool to know this. So does it make sense to apply the CD curve for sampling from a CD? It seems if i'm just ripping from the CD to WAV files no kind of eq should be necessary. I'm I correct in all this

Yes if you plug it into a dj mixer first, it will have the inverse curves in the pre-amp, already, youd only need calf emphasis if you were not using a dj mixer and going directy into your computer with just a normal preamp.

[Thad E Ginathom]

... ... ... So does it make sense to apply the CD curve for sampling from a CD? It seems if i'm just ripping from the CD to WAV files no kind of eq should be necessary.

Apparently there was something called pre-emphasis that was applied in the production of early CDs. I've never got to grips with what this was (I guess Google could tell me) because I don't think I ever needed to.

The thing with vinyl, or 78s, is there could be no don't think, because the absence of the RIAA correction would be obvious. You would think, "Who stole my bass?"

If you are ripping through a small mixer, or other device where the RIAA stuff can be turned off, try it. You'll see what I mean!